1. Field of the Invention
The invention generally relates to handling timers of periodic Routing Area (RA) updates, and more particularly, to apparatuses and methods for handling timers for RA update procedures or attachment procedures without integrity protection.
2. Description of the Related Art
In a typical mobile communications environment, a user equipment (UE), including a mobile telephone (also known as cellular or cell phone), a laptop computer with wireless communications capability, or a personal digital assistant (PDA) etc., may communicate voice and/or data signals with one or more service network. The wireless communications between the UE and the service networks may be in compliance with various wireless technologies, such as the Global System for Mobile communications (GSM) technology, General Packet Radio Service (GPRS) technology, Enhanced Data rates for Global Evolution (EDGE) technology, Wideband Code Division Multiple Access (WCDMA) technology, Code Division Multiple Access 2000 (CDMA 2000) technology, Time Division-Synchronous Code Division Multiple Access (TD-SCDMA) technology, Worldwide Interoperability for Microwave Access (WiMAX) technology, Long Term Evolution (LTE) technology, and others.
Take the WCDMA technology in compliance with the 3GPP TS 24.008 specification, v.9.2.0 (referred to herein as the TS 24.008 specification), the 3GPP TS 33.102 specification, v.9.2.0 (referred to herein as the TS 33.102 specification), and the 3GPP TS 23.122 specification, v.9.2.0 (referred to herein as the TS 23.122 specification) for example. For normal services, the wireless communications between the UE and the service network may be preferably performed when integrity protection and/or ciphering protection is on. On the other hand, in cases of emergency services or some other situations, the integrity protection and/or the ciphering protection is not mandatory for the wireless communications between the UE and the service network. In other words, the Packet-Switched (PS) messages may be transmitted without integrity protection and/or the ciphering protection. In this case, if a PS message indicating a value for a periodic RA update timer is received from the service network and the PS message is transmitted without integrity protection, then the UE may not apply the indicated value of the periodic RA update timer and the indicated value of the retry timer for the RA update or attachment procedures, and problems, such as indeterminate behavior of the UE, inconsistency of the periodic RA update timer between the UE and the service network, inappropriate prolonging of the periodic RA update procedure, and even malicious manipulation by a fake service network, etc., may occur.